This spectrum was calculated using Density Functional Theory at B3LYP 6-31G* level using Spartan ’08 software.
The maximum absorbance of Oil red O calculated using the HOMO/LUMO gap method was found to be 463nm (HOMO/LUMO gap = ~4.29E-19J).
The spectral results are in good agreement with this calculation. Although the maximum absorbance around 480nm would indicate an orange compound, the third intensity around 540nm contributes to the overall red colour of the dye.
Aniline Yellow|Disperse Orange|Oil Red|Janus Green